Aguados literally means "watery" or "diluted." While it can describe something like a drink, in this song, it's used to describe eyes.
When Paola Jara sings "Con los ojos aguados," she's painting a picture of someone with teary, swollen eyes, on the verge of crying or having just cried. It's a vivid and emotional descriptor that immediately conveys the character's sadness and vulnerability.
Paola Jara's "Ve Y Dile" is a powerful song about the lingering pain of a past love. Our singer is really going through it, talking to the moon with "los ojos aguados" [watery eyes] and asking what became of her ex. The moon, being a bit blunt, tells her, "tonta, mejor ni lo recuerdes" [silly, better not even remember him]. But our singer can't help it, she's